I rebooted today, made a few small changes in BIOS settings, and after booting into Arch again none of my hotkeys worked. No X symbols, no keypress events. The unusual hotkeys that are handled directly by BIOS (the wifi soft kill, for example, and the brightness keys) also were dead. Running "acpi_listen" showed NO acpi events. Not on lid close, not on key presses. DEAD. acpi -b still reported battery information though, so it was loaded (lsmod checked out, etc.).

My first thought was the last pre-reboot pacman -Syu, which had only updated my wacom driver. A rollback confirmed this was unrelated.

And then I thought... that BIOS change. The only thing it could be (after eliminating some other more obvious changes): I had disabled USB "always on" mode, which is the BIOS setting to provide USB charging power while in suspend mode.

So I'm curious if this seems like a bug? Worth reporting? If so where? I'm also interested if anyone else is familiar with this problem. I haven't encountered it before and didn't turn anything up in a search.